Poultry houses are used to raise birds, such as chickens or turkeys, from a young age to an adult bird, at which time the adult birds are crated and delivered to a processing plant. Modern poultry houses can be provided with automated feeding devices that deliver food for the growing birds and with automated watering devices that provide fresh supplies of water as the water is consumed by the birds. Although other species of poultry are raised in such an environment, the most common specie is the chicken.
The feed for the chickens is stored outside of the chicken house in an upright container commonly referred to as a bulk feed tank, or a feed silo. These containers are usually round and formed of bands of corrugated galvanized steel sheeting formed into an arcuate shape and connected together to form a cylindrical tank. The top of the bulk feed tank includes an inlet opening into which a feed truck can deliver bulk supplies of feed for the birds into the tank. The feed flows to the bottom of the tank by gravity into a frusto-conical outlet portion that terminates in an outlet opening, which is typically coupled to the automatic feeding devices to supply feed to the poultry within the poultry house as is prearranged.
The bulk feed tanks vary in height and in diameter according to the volume of bulk feed that the operator wants to keep on hand. Differences in height can be attained by adding additional bands of galvanized sheet metal. The joints between the respective vertical bands of sheet metal provide dividing zones that can be used to calculate the amount of feed that the partially emptied feed tank can hold. For example, for a given diameter bulk feed tank, the volume of feed between the joints can be a given tonnage of feed, such as two tons of feed. Thus, if the bulk feed tank is emptied through two joints, the operator will know that he can order four tons of feed to be delivered to that particular bulk feed tank.
For purposes of inspection, bulk feed tanks typically include vertical ladders affixed to the side of the tank. The operator will typically climb the ladder and use a hammer or other solid object to impact the side of the tank as he climbs the ladder, periodically striking the tank as he climbs. The sound of reverberation made by the sheet metal bands is different when the bulk feed is behind the band of sheet metal than when the tank does not have feed behind the sheet metal panel being struck. The mass of the feed behind the panel deadens the reverberation, while the empty portion reverberates with more of an echo. In this manner, the operator can estimate with reasonable accuracy where the level of the feed inside the tank lies without climbing to the top of the tank and looking into the inlet opening.
Manufacturers of bulk feed tanks have addressed the problem of ascertaining the volume of feed remaining in the tank by forming transparent windows into the sides of the tank so that the operator can see where the level of the feed lies within the tank. However, transparent windows only work for a limited period of time because of the dirty and abrasive nature of poultry feed which clouds and scratches the interior side of the windows until the windows are no longer transparent and, thus, are no longer effective in determining where the level of feed lies within the tank.
It would be desirable to provide a device that can be utilized to ascertain the level of feed within the interior of a closed bulk feed tank without requiring the operator to physically climb a ladder on the tank to strike the sides of the tank with a solid object, or to inspect the interior of the tank through the inlet opening at the top of the tank.